Hi all,

After merging the nvdimm tree, today's linux-next build (i386 defconfig)
failed like this:

In file included from include/linux/bits.h:6,
                 from include/linux/bitops.h:6,
                 from include/linux/kernel.h:22,
                 from arch/x86/include/asm/percpu.h:27,
                 from arch/x86/include/asm/preempt.h:6,
                 from include/linux/preempt.h:78,
                 from include/linux/spinlock.h:55,
                 from include/linux/wait.h:9,
                 from include/linux/wait_bit.h:8,
                 from include/linux/fs.h:6,
                 from include/linux/highmem.h:5,
                 from arch/x86/mm/pat/set_memory.c:6:
arch/x86/mm/pat/set_memory.c: In function 'set_mce_nospec':
include/vdso/bits.h:7:40: error: left shift count >= width of type [-Werror=shift-count-overflow]
    7 | #define BIT(nr)                 (UL(1) << (nr))
      |                                        ^~
arch/x86/mm/pat/set_memory.c:1941:59: note: in expansion of macro 'BIT'
 1941 |         decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
      |                                                           ^~~

Caused by commit

  39702cf7885c ("x86/mce: relocate set{clear}_mce_nospec() functions")

I applied the following patch for today.

From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Mon, 16 May 2022 19:00:54 +1000
Subject: [PATCH] fix up for "x86/mce: relocate set{clear}_mce_nospec() functions"

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 arch/x86/mm/pat/set_memory.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 59d9efb4257c..9200e619d8b7 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -1914,6 +1914,7 @@ int set_memory_wb(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL(set_memory_wb);
 
+#ifdef CONFIG_X86_64
 /* Prevent speculative access to a page by marking it not-present */
 int set_mce_nospec(unsigned long pfn)
 {
@@ -1959,6 +1960,7 @@ int clear_mce_nospec(unsigned long pfn)
 	return set_memory_present(&addr, 1);
 }
 EXPORT_SYMBOL_GPL(clear_mce_nospec);
+#endif
 
 int set_memory_x(unsigned long addr, int numpages)
 {
-- 
2.35.1

-- 
Cheers,
Stephen Rothwell

On Mon, May 16, 2022 at 2:11 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Hi all,
>
> After merging the nvdimm tree, today's linux-next build (i386 defconfig)
> failed like this:
>
> In file included from include/linux/bits.h:6,
>                  from include/linux/bitops.h:6,
>                  from include/linux/kernel.h:22,
>                  from arch/x86/include/asm/percpu.h:27,
>                  from arch/x86/include/asm/preempt.h:6,
>                  from include/linux/preempt.h:78,
>                  from include/linux/spinlock.h:55,
>                  from include/linux/wait.h:9,
>                  from include/linux/wait_bit.h:8,
>                  from include/linux/fs.h:6,
>                  from include/linux/highmem.h:5,
>                  from arch/x86/mm/pat/set_memory.c:6:
> arch/x86/mm/pat/set_memory.c: In function 'set_mce_nospec':
> include/vdso/bits.h:7:40: error: left shift count >= width of type [-Werror=shift-count-overflow]
>     7 | #define BIT(nr)                 (UL(1) << (nr))
>       |                                        ^~
> arch/x86/mm/pat/set_memory.c:1941:59: note: in expansion of macro 'BIT'
>  1941 |         decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
>       |                                                           ^~~
>
> Caused by commit
>
>   39702cf7885c ("x86/mce: relocate set{clear}_mce_nospec() functions")
>
> I applied the following patch for today.

Sorry I missed this. I looked for a way to avoid adding ifdefs in the
C file, but it seems that game is already lost in this file, so I'll
fold this change into the resend.

Thanks!